Chemistry Year 11 Topics

Acids:
HCL-Hydrocloric Acid
 Sulphuric Acid-H₂SO₄ 
Nitric Acid-HNO₃
Alkalis:
NaOH-Sodium Hydroxide
KOH-Potassium hydroxide
Calcium Hydoxide-Ca(OH)₂
Litmus paper in an acidic solution is red and in a alkaline solution is blue. Methyl Orange in a acidic solution is red in a alkaline solution is yellow. Phenolphthalein in an acidic solution is colourless and in an alkaline solution is pink.

The more Hydrogen ion concentration, the lower the pH.

Solute-Is the thing that dissolves .

Solvent-The liquid that does the dissolving 

Strong acid:H+ ions fully dissociate-Hydrochloric Acid.

Weak acids:H+ ions dont dissociate much-Ethanoic Acid

Bases are substances that neutralise acids to form a salt and water only. Bases include alkalis (OH-) and metal oxides.

Base+Acid--> A salt+Water

Chemical formula

Acids

Salt Formed

HCL

Hydrochloric Acid

Chlorine

H2SO4

Sulphuric Acid

Sulphate

HNO3

Nitric Acid

Nitrate

 Magnesium Oxide + Sulfuric Acid --> Magnesium Sulfate + Water

Calcium Oxide + Nitric Acid --> Calcium Nitrate + Water

Sodium Oxide + Hydrochloric Acid --> Sodium Chlorine + Water

Aqueous means dissolved in water.

Alkali is a soluble base.

metal oxides are insoluble.

Na=Sodium.

Acids + Metal Carbonate --> salt + water + carbon dioxide

Metal + Acid --> Salt + Hydrogen 

Precipitate:a solid that forms when two soluble salts react.

Precipitate reactions form percipitates

Lead Nitrate(aq) + Sodium Chloride(aq) --> Sodium Nitrate(aq) + Lead Chloride(s)

The top number is the mass number (protons+neutrons).

The bottom number is the atomic number (numberof protons (+1))

Small number is atomic number.

Atomic number also equals the same amount of electrons.

 Number of neutrons = mass number - atomic number

Isotopes:Atoms of the same element (same number of protons), but different number of protons.

Relative Atomic Mass (Ar):Average mass of an element (taking into account the different isotopes)

Relative Formula Mass (Mr):Sum of the relative atomic masses in the formula.

CO2=12+(16x2)=44-Relative Formula Mass

H2O2      2:2      1:1      empircal formulae:HO

Empirical Formulae:Simplest ratio of the different atoms of each element in a substance. 

                                Ca                  Cl

Mass                     10.0g             17.8g              CaCl->Calcium Chloride

Ar                             40                 35.5

mass/Ar                 10/40           17.8/35.5

"    "                          0.25                0.5

Divide both by          0.25/0.25        0.5/0.25            =CaCl2

smallest number 

Ratio                           1                       2

Mr=Relative Formulae mass

Empirical formulae for glucose and it relative formulae mass is 180.

Empirical Formulae=CH2O                 12+(1x2)+16=12+2+16=30

Relative formulae mass=180

Molecular Formula=180/30=6

C 6 H 12 O 6

Concentration (g/dm cubed)=Mass of solute(g)/volume of solvent(dm cubed)

cm cubed --> divided 1000 --> dm cubed

50cm cubed --> divided 1000 --> 0.05dm cubed

- Mass is always conserved in a reaction. If the mass seems to go down it is a non-enclosed system. (e.g. gas has escaped.)

2Al + 3Cl2 --> 2AlCl 3

           213--> 267

3Cl2 = 3(35.5x2)=213

AlCl 3 = 2(27+(35.5x3))=267

xg=53.4g

213=267

213x53.4=267x X

11347.2/267= X

X=42.6

1 mole=6.023 x 10 power 23

1 gram of hydrogen atoms=6.023x10 power 23 atoms= 1 mole of H atoms.

12 grams of carbon atoms=6.023x10 power 23 atoms

                                           =1 mole

24 grams of carbon=2 moles

6 grams of carbon=0.5 moles

1 mole of atoms of an element will have the same mass in grams as the mass number of that element.

Avogadro's constant=6.023x10 power 23  --  no. of particles in 1 mole.

Mass (g)

------------------------------------------

             No. of moles       x       Ar/Mr                   

Ar-relative atomic mass

Mr-relative formula mass

Limiting Reactant-The reactant that determines the amount of product formed in a chemical reaction. Any other reactants will be present in excess.

2NH4 CL + Ca(OH)2 --> 2NH3  + CaCl2  +  2H 2 O

1.50g                            |    4.00

53.5=14+(4x1)+35.5     |   40+(16x2)+2=74

1.50/53.5=0.03moles   |  4.00/74=0.05

Gold,Silver=Unreactive

Aluminium,Iron=Reactive

Electrolysis:Using electricity to break down a substance e.g. Aluminium oxide into aluminium and carbon dioxide.

To have electricity you need a flow of charge.

(+ electrode=anode)  (-electrode=cathode)

Anode=2Cl- --> Cl2 + 2e-

Cathode=Na+  +  e-  -->  Na

Anion=negative ion               

Cation=positive ion

Electrolyte:The substance that we are splitting up e.g. sodium chloride.

When an ion goes to an electrode it becomes neutral. Ions lose their charge as they reach the electrodes.

Displacement reaction (swap). Zinc has displaced the copper because zinc is a more reactive metal then copper.

Zinc + Copper sulphate --> Zinc Suphate + Copper

Iron Oxide + Carbon --> Iron + CArbon Dioxide

An ore is a rock that contains enough of a compound to extract a metal for profit.

Phytoextraction:

• Metal compounds are in the ground in a small amount.
• Plants are planted over the metal in the ground. The roots extract the metal.
• They light the plants on fire, carbon dioxide is emissioned into the atmosphere as a affect of burning the plant.
• From there they extract the metal out of the ash.

Bioleaching:

• They apply the bacteria (leachate) over the metal compounds in the ground.
• It displaces copper using iron.
• Purify by electrolysis.

Oxidation

Is

Loss of electrons

Reduction                      = Oil Rig

Is

Gain of electrons

Reduction=Loss of oxygen

Recycling Materials

Advantage                                                                  Disadvantage

Less waste metals end up in landfill sites.    |      Mining can damage landscapes

Less pollution is produced.     |        Cost + Energy used in collecting and transporting and sorting 

Some reactions are reversible-can go in both forward and backward directions.

Haber Process:The production of ammonia by reacting nitogen + Hydrogen in a reversible reaction.

Factor that affect position of equilibrium:

-Concentration

Increase conc. of reactants, equilibrium move to the right.

Increase conc. of products equilibrium shifts to the left.

If you increase the pressure the reaction moves in the direction of the least molecules of gas.

Noble gases-any element in group 0

Properties:

• Colourless
• Have very low melting and bioling points.
• Poor conductors.

Helium=Ballons=have low density.

Neon=produces red-orange light, illuminated signs=long lasting.

Argon=denser then air=goes into the top part of a wine bottle.

Kryptone=Photography=white light produced when electricity passes through it.

• Chlorine-green gas.
• Bromine-Brown liquid.
• Iodine-Purple/black solid.

It gets darker as you go down, and is more reactive as you go up.

Each element comes in twos.

Hydrogen + Halogen --> Hydrogen Halide.

Hydrogen + Chlorine --> Hydrogen Chloride.

The trend in reactivity is that as you go up the group it becomes more reactive due to there being less shells for an electron due to the nucleus.

Group 1:More reactive as you move down. As you go down there is a longer distance between the nucleus and the outer electron so it is easier to lose.

Metal + Water --> metal hydroxide + hydrogen

Sodium + Water--> Sodium hydroxide + Hydrogen

2Na + water --> 2NaOH + H2

Reactants need to collide with enough energy to react. The minimum amount of energy neede is called the activation energy.

A + B --> C

Factors that affect the rate of reaction

Concentration- Increasing the concentration of a solutions increase the rate of reaction. If the concentration is higher the more collisions occur.

Surface area- Increasing the surface area to volume ratio, by decreasing the size of solid pieces while keeping the total volume of solid the same, increase the rate of reaction.

Pressure-Increasing the pressure of gases increases the rate of reaction.The reactant particiles are squeezed closer together so collisions occur more often.

Temperature-The reactant particles speed up and have more energy. They therfore collide more often and more particles have enough energy to react when they collide.

Endothermic Reactions-

Energy goes into the the reaction. Activation energy goes up and then goes down a bit to it overall energy.

Exothermic Reaction-

Activation energy goes up then the overall energy goes down.

A substance that speeds up the rate of reaction with out itself being used up.

Catalystic Converter:

2NO --> N2 + O 2

2NO2 --> N2 + 202

2CO + O2 --> 2CO2

• A mixture of different hydrocarbons.
• Hydrocarbons:A compound made from hydrogen and carbon only.
• Fraction        Use
• Gases          Domestic heating and cooking
• Petrol           Fuel for cars
• Keroscene    Fuel for aircrafts
• Diesel Oil      Fuel for some cars and trains
• Fuel Oil        Fuel for large ships and power stations
• Bitumen       Surfacing roads and roafs.
• Intermolecular-Between molecular
• Small molecules have low boiling points
• heat gradient in the fractionating column

CnH2n+2

Methane-CH4

Ethane-C2H6

Propane-C3H8

Butane-C4H10

Pentane-C5H12

Monkeys

Eat

Peanut

Butter 

Politly

• Alkanes are hydrocarbons with single bonds only.
• The longer the carbon chain, the higher the boiling point.

Combustion

Complete Combustion

Methane + Oxygen --> Carbon Dioxide + Water

CH4 + O2 --> CO2  +  2H2O

Incomplete Combustion (When there is a limited supply of oxygen)

Methane + Oxygen --> Carbon Monoxide + water

2CH4 + 3O2 --> 2CO + 4H2O

Problems with incomplete combustion:

• Carbon monoxide is clearless and is extremely toxic.
• This gas combines with haemaglobins in red blood cells to stop them conbining with the oxygen.
• Soot can block pipes carrying waste.
• If it collects in the lung it can cause breathing problems.

-There are impurities in the fossil fuel.

-Sulphur dioxide mixes with the rain in the sky causing acid rain.

C10H22    is boiled in a high temp. it also uses a catalyst. Then it is broken down into an alkane(single bond only) and a hydrocarbon with a double bond (alkene) this can be used to make polymers e.g. plastic.

• Alkanes are saturated (their carbon atoms are joined by single bonds)
• Alkenes are unsaturated (They contain a carbon-carbon double bond)

The greenhouse effect.

• Energy is transferred from the sun to the earth.
• Some energy is reflected back to space.
• Earth emits energy.
• Some emitted energy is transferred to space.

Effects of global warming:

Ice caps melt + sea levels rise.

Plants can become instinict

Some area will get hotter 

Some areas will get wetter

more extreme weather events.